Sorry to bring bad news, but a Wasserschutzpolizei visor should not have carmine pipings. The interior label is a fantasy piece inspired by labels found in political items. (Police uniform items did not fall under RZM control. Also, notice that the fakers didn't even manage to spell Polizei-Dienstmütze right.)

I'm afraid this is a fire brigade cap (whether from the Third Reich era or post-war, I cannot tell) with insignia that don't belong there.